Several such types of equipment are known and the present invention aims at using an arrangement for burning brushwood waste. Two cylindrical units are used here, arranged concentrically so that a core area and an annular space are formed. Both the wails forming said unit are perforated and the annular space is filled with brushwood waste which is fed into the space from below. The brushwood waste is ignited and combustion is maintained by air being allowed to flow through perforations in the two pipes. This known arrangement provided the impulse to develop a completely new type of heating equipment for burning pellets.